The BBC could face prosecution over obscene phone calls that Jonathan Ross and Russell Brand made to 78-year-old Fawlty Towers actor Andrew Sachs.

The controversial presenters left a series of lewd messages on Mr Sachs’s answerphone claiming, in shockingly explicit language, that Brand had had sex with his granddaughter, Georgina.

Mr Sachs, who played waiter Manuel in the classic sitcom, was left deeply upset by the crude calls – which were also broadcast to about two million listeners to Brand’s Radio 2 show.